ADHESIVE ARTICLES HAVING RECYCLABLE OR COMPOSTABLE RELEASE LINERS - Patent application

Abstract

The adhesive article attachable to a substrate can include an adhesive layer attachable to a major surface of the substrate and a releasable liner in contact with the adhesive layer. The releasable liner has a release layer and a biodegradable polymer layer applied to the release layer. The release layer defines a structured surface in contact with the adhesive layer.

Description

[Technical field]

[0001] Adhesive articles are useful for adhering desired articles to substrates, among other applications. Release liners are used to protect the adhesive properties of the adhesive itself. These liners can be easily removed by the user prior to use. Summary of the Invention

[0002] In one aspect, an adhesive article attachable to a substrate includes an adhesive layer attachable to a major surface of a substrate and a releasable liner in contact with the adhesive layer. The releasable liner has a release layer and a biodegradable polymer layer applied to the release layer. The release layer defines a structured surface in contact with the adhesive layer.

[0003] In another aspect, a method of forming an adhesive article includes providing an adhesive layer and laminating a releasable liner to the adhesive layer. The releasable liner includes a release layer and a biodegradable polymer layer applied to the release layer. The release layer defines a structured surface in contact with the adhesive layer. [Brief description of the drawings]

[0004] [Figure 1] 1 is a schematic cross-sectional side view of an adhesive article. [Diagram 2] FIG. 2 is a schematic cross-sectional side view of a removable liner. [Diagram 3] 1 is a side schematic view of a method of forming an adhesive article. [Figure 4] 1 is a side schematic view of another method of forming an adhesive article. [Diagram 5] 1 is a schematic cross-sectional side view of a tape-type adhesive article. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0005] 1 is a side cross-sectional schematic view of an adhesive article. The adhesive article 100 includes a substrate 110, an adhesive layer 120 attached to the substrate 110, and a releasable liner 130 applied to the adhesive layer 120. In some embodiments, the substrate 110 is optional. In some embodiments, an adhesive article including the adhesive layer 120 and the releasable liner 130 without the substrate 110 may provide a single liner adhesive transfer tape. In some embodiments, the adhesive article may include one, two, or more of the substrate, adhesive layer, and releasable liner.

[0006] The adhesive article 100 may include any suitable substrate. In some embodiments, the substrate 110 may be or include a polymeric material. In some embodiments, the substrate 110 may be a separate liner, which may provide a dual liner adhesive transfer tape.

[0007] In some embodiments, the substrate 110 may be a backing layer or core that may include a polymeric foam material to provide a double-sided adhesive tape (see FIG. 5). Suitable polymeric materials include polyethylene terephthalate (PET), high or low density polyethylene or polyester in general, polycarbonate, polyvinyl chloride (PVC), polystyrene, polylactic acid (PLA), or cellulose acetate. Other suitable materials include paper or wood pulp materials, nonwoven or woven webs of natural or synthetic fibers.

[0008] Suitable polymer foam materials include polycarbonate, polyacrylic, polymethacrylic, elastomers, styrene block copolymers, styrene-isoprene-styrene (SIS), styrene-ethylene / butylene-styrene block copolymer (SEBS), polybutadiene, polyisoprene, polychloroprene, styrene and diene-based styrene-butadiene rubber (styrene-butadiene rubber). random copolymers of styrene and diene-based styrene-butadiene rubber (SBR), block copolymers of styrene and diene-based styrene-butadiene rubber (SBR), ethylene-propylene-diene monomer rubber, natural rubber, ethylene propylene rubber, polyethylene-terephthalate (PET), polystyrene-polyethylene copolymers, polyvinylcyclohexane, polyacrylonitrile, polyvinyl chloride, polyurethane, aromatic epoxies, amorphous polyesters, amorphous polyamides, semi-crystalline polyamides, acrylonitrile-butadiene-styrene (ABS) copolymers, copolymers of ethylene and vinyl acetate, also called ethylene-vinyl acetate (EVA), polyethylene-vinyl acetate (PEVA), low-density polyethylene (LDPE), polypropylene (PP), such as expanded polypropylene (EPP) and polypropylene paper (PPP), expanded polystyrene (expanded polystyrene), Polystyrene (PS), such as polystyrene (EPS) and extruded polystyrene (XPS) and sometimes polystyrene paper (PSP), nitrile rubber, such as in copolymers of acrylonitrile (ACN)Examples of suitable adhesives include butadiene, polyphenylene oxide alloys, high impact polystyrene, polystyrene copolymers, polymethylmethacrylate (PMMA), fluorinated elastomers, polydimethylsiloxanes, polyimides, polyetherimides, amorphous fluoropolymers, amorphous polyolefins, polyphenylene oxide, polyphenylene oxide-polystyrene alloys, or mixtures thereof. The foams can be formed as coextruded sheets with adhesive on one or both sides of the foam, or the adhesive may be laminated to the foam. When the adhesive is laminated to the foam, it may be desirable to treat the surface to improve adhesion of the adhesive to the foam or any other type of backing. Such treatments are typically selected based on the nature of the adhesive and the nature of the foam or backing material, and include primers and surface modifications (e.g., corona treatment, surface abrasion). Additional foam tape structures may include those described in U.S. Pat. No. 5,602,221 (Bennett et al.), U.S. Pat. No. 4,223,067 (Levens), and U.S. Pat. No. 6,103,152 (Gehlsen et al.), which are incorporated herein by reference.

[0009] The substrate 110 may be substantially transparent, may have a high degree of diffusion (e.g., exhibiting high haze and / or low transparency), or may include one or more pigments or colorants that render the substrate translucent or even opaque.

[0010] The substrate 110 may be printed or printable. The adhesive article 100 may include an ink layer applied to the side of the substrate 110 or embedded in the substrate. In some embodiments, the adhesive layer 120 may be applied to a major surface of the substrate 110 and an ink layer may be on the major surface of the substrate 110 opposite the adhesive layer 120.

[0011] Substrate 110 may be formed through any suitable process and to any suitable size, shape, or thickness. In some embodiments, substrate 110 may be formed through a melt extrusion or blow extrusion process. In some embodiments, substrate 110 may be formed through a calendaring process. In some embodiments, substrate 110 may be formed through a casting (e.g., solvent casting) process. In some embodiments, substrate 110 may be formed from an additive manufacturing process.

[0012] In some embodiments where the adhesive article is in the form of a tape or film, the substrate 110 may be between 10 micrometers and 3000 micrometers thick. In some embodiments, the substrate 110 may be a portion of a larger material or surface. In some embodiments, the substrate 110 may be several millimeters, several centimeters, or even several meters thick. For example, the substrate 110 may be a portion of a floor, wall, or ceiling. The substrate 110 may be a portion of any object (vehicle, wall, box, electronic device, for example) as long as the selected adhesive is capable of adhering to the surface of the substrate.

[0013] Adhesive layer 120 may be any suitable material and may be formed through any suitable process. In some embodiments, adhesive layer 120 comprises an epoxy or optically clear adhesive. In some embodiments, adhesive layer 120 is or comprises a pressure sensitive adhesive layer. In some embodiments, adhesive layer 120 is or comprises an acrylic pressure sensitive adhesive layer. In some embodiments, adhesive layer 120 is formed through a solvent coating process. In some embodiments, adhesive layer 120 is formed through an extrusion (melt or blow) process. Adhesive layer 120 may have any suitable thickness. Adhesive layer 120 may be selected for its rheological or optical properties. The adhesive layer may include pigments, dyes, or other colorants. In some embodiments, the adhesive may be 10 micrometers to 1550 micrometers thick. In some embodiments, the adhesive may include partially embedded microbeads made from materials such as glass, ceramic, or polymeric resins, or aggregates thereof held together with a suitable binder material. In some embodiments, such microbeads may have a refractive index matched to that of the adhesive layer.

[0014] In some embodiments, particularly if the substrate does not inherently bond well to the adhesive chemistry, some embodiments may optionally include a prime layer on the substrate. The prime layer, often also referred to as a primer layer or tie layer, may be any suitable material or composition having any suitable thickness. The choice of the prime layer is to ensure sufficient adhesion between the substrate and the adhesive layer (to prevent ply-bond failure) and sufficient adhesion to bond to both. In some embodiments, the prime layer may include a polyamide or copolyamide. Certain materials may alternatively or additionally be useful as a barrier layer to prevent migration of plasticizers, water, solvents, or other contaminants from the side of the substrate opposite the adhesive layer to the adhesive layer. Such a prime layer may be extremely thin, for example, less than 10 micrometers thick, less than 6 micrometers thick, less than 5 micrometers thick, less than 4 micrometers thick, less than 3 micrometers thick, less than 2 micrometers thick, or even less than 1 micrometer thick. Such layers may be solvent cast, coated, or even extruded or coextruded (with one or more of the other layers).

[0015] The releasable liner 130 is intended to be placed over and in contact with the adhesive layer 120 to protect the exposable (and adhesive) side of the adhesive layer before the adhesive layer is attached to its final surface. Such a releasable liner is therefore peelable and removable by the user at or near the time of installation. Installation may also include laminating the adhesive article (without the releasable liner) to another film or film stack.

[0016] The releasable liner 130 may be constructed to be easily releasable, but may also be adapted to maintain contact with the adhesive layer until removal. In some embodiments, the average peel force required to remove the releasable liner 130 from the adhesive layer 120 is 1000 g / inch, 800 g / inch, 500 g / inch, 200 g / inch, 150 g / inch, 135 g / inch, 100 g / inch, 50 g / inch, 30 g / inch, or even 10 g / inch or less.

[0017] This peel force can be affected not only by the material, but also by any physical structure present on the adhesive interface surface of the release liner (described in more detail below), and by environmental aging (e.g., long-term exposure to temperature and humidity). The impact of the peel can also be an important parameter in some applications. Small variations in the peel force correspond to a smoother (less impactful) peel. In some embodiments, the root mean square deviation from the average peel force is 200 g / inch, 100 g / inch, 50 g / inch, 20 g / inch, 10 g / inch, 5 g / inch, or even 1 g / inch or less.

[0018] The releasable liner 130 may be formed from any suitable material. Silicone and other existing release materials are not readily recyclable in many commercial recycling streams. However, many recyclable materials alone result in unacceptably high (or shocking) release. The combination of a biodegradable polymer layer and a relatively thin release layer, which may be a non-biodegradable material, may provide the releasable liner 130 with sufficient releasability and compostability or recyclability.

[0019] The releasable liner 130 includes two or more layers. As shown in Figure 1, the releasable liner 130 includes two layers: a release layer 132 and a biodegradable polymer layer 134 applied to the release layer 132. As used herein, the term "biodegradable" refers to a material that breaks down or degrades in the environment, for example, by exposure to bacteria or other organisms.

[0020] In some embodiments, the releasable liner 130 may be compostable. In particular, the biodegradable polymer layer 134 may be made of a compostable material. As used herein, the term "compostable" refers to a material, composition, or article that meets the standards ASTM D6400 or ASTM D6868. It should be noted that these two standards are applicable to different types of materials, so a material, composition, or article usually only needs to meet one of them, whichever is most applicable, to be "compostable" as defined herein. In particular, a compostable material, composition, or article also meets the ASTM D5338 standard. In particular, a compostable material, composition, or article also meets one or more of the EN 12432, AS 4736, or ISO 17088 standards. More particularly, a compostable material, composition, or article also meets the ISO 14855 standard.

[0021] The term "compostable" as used herein is not the same as the term "biodegradable." Something that is "compostable" should degrade within the time specified by the above standards into a material that has toxicity, particularly phytotoxicity, consistent with the above standards. The term "biodegradable" does not specify the time that a material should degrade, nor does it specify that the compound that degrades pass any standard for lack of toxicity or environmental harm. For example, a material that meets the ASTM D6400 standard should pass the tests specified in ISO 17088, which addresses the "presence of high levels of regulated metals and other harmful components," while a material that is "biodegradable" may have any level of harmful components. In some embodiments, the release liner 130 may contain less than 0.5%, or even less than 1%, of non-recoverable or non-biodegradable material and still be compostable.

[0022] Because the biodegradable polymer layer 132 is not in contact with the adhesive layer 120, the biodegradable polymer layer 132 may be selected for properties other than its surface energy (i.e., its releasability from a particular adhesive layer). In some embodiments, the biodegradable polymer layer 132 may be or include a commercially recyclable polymeric material or a bioplastic.

[0023] Non-limiting examples of suitable materials for use in the biodegradable polymer layer 134 include polybutylene succinate (PBS), poly(lactic acid) (also known as PLA, which as used herein is intended to encompass both poly(lactic acid) and poly(lactide)), poly(glycolic acid) (which as used herein is intended to encompass both poly(glycolic acid) and poly(glycolide)), poly(caprolactone), poly(lactide-co-glycolide), copolymers of two or more of lactic acid, glycolic acid, and caprolactone, polyhydroxyalkanoates (PHAs), polyester urethanes, degradable aliphatic-aromatic copolymers, poly(hydroxybutyrate) (PHB), copolymers of hydroxybutyrate and hydroxyvalerate, poly(ester amides), polyhydroxyhexanoates (PHH), cellulose esters, and cellulose.

[0024] In some embodiments, the releasable liner 130 may be recyclable. As used herein, the term "recyclable" refers to voluntary or regional guidelines regarding acceptable materials. Under some guidelines, "recyclable" refers to a liner that has less than 15% material that cannot be recovered for recycling. The releasable liner 130 may contain less than 15% non-biodegradable materials.

[0025] The peelable liner 130 may, for example, include polybutylene succinate (PBS) in the biodegradable polymer layer 134. PBS is a biodegradable and compostable thermoplastic aliphatic polyester that naturally degrades into water and carbon dioxide in the presence of microorganisms, such as, for example, Amycolatopsis sp., HT-6, and Penicillium sp., strain 14-3. PBS has a lower melting point (115° C.) than other biodegradable bioplastics, such as polylactic acid (PLA), making it more easily extrudable.

[0026] In some embodiments, PBS and small amounts of wax (especially vegetable-based waxes) can provide acceptable or "premium" release performance without requiring landfilling of discarded liners. In some embodiments, the releasable liner 130 also includes 0.5 to 5 polymer weight percent wax. Suitable waxes include ethylene bis(stearamide) (EBS), castor wax, polyamitic acid, linoleic acid, arachidonic acid, polantolic acid, butyric acid, stearic acid, and triglycerides. In some embodiments, the wax is a vegetable-based wax. Suitable vegetable waxes include castor wax, EBS, and soy wax.

[0027] The release layer 132 may be made of or include any suitable material to facilitate releasability, such as PBS, silicone, silicone polyoxamide, or octadecylcarbomylethyl acrylate (ODCEA). In some embodiments, the release layer 132 is made of or includes a non-biodegradable material, such as silicone. If present in the releasable liner 130, the amount of silicone or other non-biodegradable material may be limited to a certain maximum percentage to facilitate composting or recycling. In some embodiments, the ratio of the weight of the release layer 132 to the total weight of the releasable liner 130 is less than 15%, which may facilitate recyclability. In some embodiments, the ratio of the weight of the release layer 132 to the total weight of the releasable liner 130 is less than 1%, or even less than 0.5%, which may facilitate compostability.

[0028] In some embodiments, the release liner 130 may also include a woven or nonwoven material formed from natural fibers. In some embodiments, the release liner 130 may include wood pulp or a paper-like material. As shown in FIG. 1, the release liner 130 includes a paper layer 136. A biodegradable polymer layer 132 may be formed on the paper layer 136. Any suitable paper material that is biodegradable, compostable, or recyclable may be used.

[0029] In some embodiments, the release liner 130 may also include another biodegradable polymer layer 138 applied to the paper layer 136 opposite the biodegradable polymer layer 132. Some recycling guidelines or standards may only prefer the presence of the biodegradable polymer layer 132 and the paper layer 136. Some composting guidelines or standards may prefer the addition of the biodegradable polymer layer 138 to coat both sides of the paper layer 136 with a biodegradable polymer.

[0030] The adhesive article 100 may be formed using any suitable technique. In some embodiments, a technique for forming the adhesive article 100 may include laminating a releasable liner 130 to the adhesive layer 120.

[0031] This technique may also form a releasable liner 130, which may include applying (or coating) a release layer 134 onto the biodegradable polymer layer 132. The release layer 134 and the biodegradable polymer layer 132 may be embossed.

[0032] The adhesive article 100 may be used in any suitable manner. For example, the adhesive article 100 may be used by removing the releasable liner 130 from the adhesive layer 120 and laminating the adhesive layer 120 onto the surface of an object.

[0033] As can be seen in Figures 1 and 2, the releasable liner may include a structured surface. Figure 1 shows a releasable liner 130 that includes a structured surface 140. Figure 2 shows a releasable liner 200 that includes a structured surface 234.

[0034] 2 is a cross-sectional schematic side view of a releasable liner 200. The releasable liner 200 includes a release layer 232 that includes a structured surface 234. The release layer 232 is optionally disposed on a biodegradable polymer layer 236. Although not shown, the releasable liner 200 may also include a paper layer 136 (FIG. 1) and another biodegradable polymer layer 138 (FIG. 1).

[0035] The structured surface 140, 234 may include raised features that define the structured surface of the release layer. The structured surface 140, 234 disposed on one of the major surfaces of the releasable liner may include any suitable micro- or macrostructure. In some embodiments, the structured surface 140, 234 includes microstructures to impart air-bleed properties, which may be posts, prisms, raised rails, linear rail segments, or any other suitable shape. In some embodiments, at least one dimension of the structure is between 1 and 1000 micrometers. In some embodiments, the structured surface 140, 234 may include a pseudo-random or rough textured surface that may impart air-bleed properties. In some embodiments, the structured surface 140, 234 may include bead-filled impressions that may impart slideability.

[0036] The structured surface 140, 234 may be formed from any suitable process, including additive manufacturing (e.g., 3D printing), negative manufacturing (e.g., etching), microreplication (e.g., continuous cast and curing), embossing, etc. In some embodiments, one or more of the shape, size, and relative positioning of the microstructures may vary across one or more directions of the releasable liner.

[0037] The structured surface 140, 234 can significantly affect the peel force required to peel (or remove or peel) a releasable liner. Because the surface area in contact with the adhesive (at least for certain structural geometries) is reduced, the peel force required (on a per unit length basis) can be significantly reduced.

[0038] The structured surface 140, 234 may have alternative or additional advantages. Certain commercially available films include structured adhesives, where microfeatures may provide application features such as air evacuation and slidability (e.g., IJ180Cv3 from 3M Company with Comply™ and Controltac™ adhesives). In some cases, these structured features are formed by interlocking a structured liner with a substantially feature-free adhesive layer. The features are embossed, and the adhesive receives a structured pattern that is the inverse of the structured liner. For example, interlocking a structured liner with rails or ridges to create channels in the adhesive layer. However, this structured interface surface may provide even more contact surface area between the liner and the adhesive, and therefore design tolerance may be further dependent on material selection. The specific selection of structure shape and size, as well as adhesive thickness and flowability, may help prevent the adhesive from completely wetting the surface structure, thereby reducing the effect that closely interlocked structures may have on peeling. For example, in some embodiments, the structures are shaped and sized such that they move a greater volume per unit area between the support surface and the planar land area than the adhesive volume for that same unit area.

[0039] The structured surfaces 140, 234 are formed from or on the respective release layers. The release layer 232 includes materials as described above in connection with the release layer 134. The release layer 232 may be formed on a biodegradable polymer layer 236. The combination of the very thin release layer 232 and the biodegradable polymer layer 236 may be structured to provide desirable release and compostability or recyclability.

[0040] 3 is a side schematic view of a method of forming an adhesive article. A substrate 310 having an adhesive layer 320 disposed on a major surface thereof is laminated with a releasable liner 330. Such lamination can be done in batches or as a continuous process.

[0041] Figure 4 is a side schematic view of another method of forming an adhesive article. A substrate 410 is laminated to a releasable liner that includes an adhesive layer 420 coated thereon. As with the process shown in Figure 3, such a process can be performed in a batch process or in a continuous (roll-to-roll) process as well.

[0042] 5 is a schematic side cross-sectional view of an adhesive article 500, which is a tape including a releasable liner. As shown, the adhesive article 500 includes a substrate 110 (e.g., as a backing layer), a first and a second adhesive layer (adhesive layer 120 and adhesive layer 520), and a first and a second releasable liner (releasable liner 130 and releasable liner 530) to provide a double-sided adhesive tape with a dual liner. The second releasable liner 530 may be the same or similar in terms of material or construction as the releasable liner 130.

[0043] Substrate 110 may have a first major surface and a second major surface opposite the substrate. Adhesive layer 120 and adhesive layer 520 may be disposed on the surface opposite substrate 110. Adhesive layer 120 may be disposed on the first major surface. Adhesive layer 520 may be disposed on the second major surface. Releasable liner 130 may be disposed on adhesive layer 120 on the opposite side of substrate 110. Releasable liner 530 may be disposed on adhesive layer 520 on the opposite side of substrate 110.

[0044] One of the first and second releasable liners 130, 530 may be optional. In some embodiments, the adhesive article 500 includes only one of the releasable liners 130, 530, providing a double-sided adhesive tape with a single liner.

[0045] Any suitable adhesive article material or configuration for the tape, including adhesive transfer tape or double-sided tape, may include one or more liners, including releasable liner 130 or releasable liner 530, such as the materials and configurations described in International Publication No. WO 2019 / 193468, published October 10, 2019, which are incorporated by reference in their entirety herein.

[0046] Descriptions of elements in the figures should be understood to apply equally to corresponding elements in other figures unless otherwise indicated. The present invention should not be considered limited to the particular embodiments described above, as such embodiments have been described in detail to facilitate explanation of the various aspects of the invention. Rather, the present invention should be understood to encompass all aspects of the invention, including various modifications, equivalent processes, and alternative devices, included within the scope of the invention as defined by the appended claims and their equivalents. EXAMPLES

[0047] Biodegradable, peelable liners were prepared and tested, and the release properties were measured and are presented in the examples below.

[0048] These examples are for illustrative purposes only and are not intended to limit the scope of the appended claims. All parts, percentages, ratios, etc. in the examples and elsewhere herein are by weight unless otherwise indicated. The following abbreviations are used herein: um or μm = micrometers, min = minutes, in = inches, gms = grams, psi = pounds per square inch, KPa = kilopascals, kg = kilogram, MW = molecular weight. [Table 1]

[0049] Test Method Sample preparation and conditioning Liner Replacement Tape a 10cm x 10cm embossed liner, pattern side up, onto a 15cm x 15cm sheet of 3mm thick PC. Cut into 3-2.5cm x 15cm strips of IJ180-10. Remove the liner and, using moderate pressure, squeeze each strip by hand onto the taped liner, bringing the adhesive side of each into contact with the embossed side of the liner.

[0050] Sample conditioning: Place the sample under a 22.7Kgf sandbag with the three strips face down (pattern up) on an embossed liner taped to a flat PC substrate, exerting a 190Kgf / m force on the sample placed between the surface of the sandbag and the supporting PC sheet. 2 The contact area is 30cm x 40cm, which is a flat area that approximates the uniform pressure of 100g. Keep in a constant temperature and humidity room (72°F, 50% RH) for one week.

[0051] Measure the peel force of the peel: Using a hand held scale, mount the sample and pull at 180 degrees at a speed of 115 cm / min. Record the average peel force.

[0052] Measurement of adhesive channel depth and liner ridge height A white light interferometer (available as ContourGT with VISION64 operation and analysis software from Bruker) was used to evaluate and report the adhesive groove depth and liner ridge height. Sample topography was acquired using a measurement function while using a 10x lens. The following procedure was used to report the ridge height and / or groove depth depending on the sample type. 1) Use Terms Removal for curvature and tilt 2) Set iterations to 20 and use Data Restore 3) On a 2D chart, set a draw profile across a two-point polyline and a channel / ridge 4) The average of five measurements is reported as the ridge height and / or channel depth depending on the sample type.

[0053] Liner ridge height = average liner ridge height.

[0054] Adhesive groove depth on the same day as removal = average of adhesive groove depths measured on the day the film was removed from the liner

[0055] Adhesive Groove Depth After 2 Weeks = Average adhesive groove depth measured after samples were left open faced (adhesive exposed) at room temperature conditions for 2 weeks.

[0056] Examples E1 to E3 and Example C1 Examples E1-E3 were made by extruding 45 micrometer PBS onto S1, which was then passed through cold nip rollers. A four-zone single screw extruder was used with an increasing temperature profile of 200°F, 350°F, 450°F, and 500°F. The extruder die temperature was 500°F and the extrusion speed was 600 ft / min. The nip roller temperature was 150°F. The resulting material was then corona treated to improve the bonding of the PBS to the substrate. The resulting films were then gravure coated with RC1, RC2, or RC3 to obtain E1, E2, and E3, respectively. The target thickness of the gravure coating was less than 1 micron. The gravure coated material was then dried in a blower oven, first at 150°F for 20 seconds, then at 180°F for 10 seconds. C1 was a PCK liner. After the samples were prepared, they were subjected to peel testing and structural measurements (Table 2).

[0057] Example E4 Example E4 was made by the process used for E1-E3, using RC3 for coating. A pattern was embossed by the same method disclosed in US Patent Application Publication No. 2021 / 0017426(A1) for the preparation of Example 1. A pattern was embossed into the release liner by passing the release liner between a silicone rubber roll and an engraved metal roll. The pattern was a series of channels that were unidirectionally linear and approximately 23 microns in height. The pressure sensitive adhesive solution (A1) was slot die coated onto the structured side of the embossed release liner and dried using a continuous coater / dryer line using the same conditions as specified in Example 1 of US Patent Application Publication No. 2021 / 0017426(A1). The adhesive side of the adhesive coated release liner E4 was then laminated to a film (F1) at room temperature. [Table 2]

[0058] Liner peeling measurement Lab Master Release & Adhesion Tester (Version 1.6.0) was used to measure the liner release from the prepared samples. Example E4 was evaluated by this method. E4 was tested after conditioning in a controlled humidity (approximately 50%) and temperature (approximately 73°F) environment for 24 hours. This test measured the peel force of the adhesive from the liner at a 90 degree angle and a 180 degree angle. A strip of 3M 9425 Removable Double-Sided Tape was applied to the thread using a PA-1 3M squeegee. Each sample was then applied to the masking tape on the thread using a PA-1 3M squeegee. The sample was rubbed back and forth with the squeegee three times to promote adhesion to the thread.

[0059] For the 90 degree angle, the samples were pulled using a thread speed of 255 in / min. The adhesive coated film was pulled from the liner. The samples were cut to 1 inch by 15 inches (CD x MD). The test values ​​were recorded as grams per inch. The average was taken from three replicates and is reported in Table 3 below.

[0060] For the 180 degree angle, the samples were pulled using a thread speed of 90 in / min. The liner was pulled from the adhesive coated film. The samples were cut to 1 in. by 15 in. (CD x MD). Test values ​​were recorded as grams per inch. The average was taken from three replicates and is reported in Table 3 below.

[0061] Reference was made to ASTM D3330 / D3330M-04 (Test Method D: Adhesion to Liner). [Table 3]

[0062] For E4 peeled at 180 degrees, the peel force was approximately 16.7 g / inch. 16.7 g / inch peel force. For E4 peeled at 90 degrees, the peel force was approximately 38.3 g / inch. The resulting peel forces are excellent for graphic film applications.

[0063] Thus, various embodiments of adhesive articles with recyclable or compostable release liners are disclosed. Reference is made herein to a series of accompanying drawings that form a part of this disclosure, at least to those skilled in the art who will appreciate that various adaptations and modifications of the embodiments described herein are within or do not depart from the scope of this disclosure. For example, aspects of the embodiments described herein can be combined with each other in various ways. It is therefore to be understood that within the scope of the appended claims, the claimed invention may be practiced otherwise than as expressly described herein.

[0064] Unless otherwise indicated, all numbers expressing feature sizes, quantities, and physical properties used in the specification and claims can be understood as being modified by either the term "exactly" or "about." Accordingly, unless specifically indicated to the contrary, the numerical parameters set forth in the above specification and appended claims are approximations that can vary depending upon the desired properties sought to be obtained by those of ordinary skill in the art utilizing the teachings disclosed herein, for example, within typical ranges of experimental error.

[0065] The recitation of numerical ranges by endpoints includes all numbers subsumed within that range (e.g., 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, and 5) and any range within that range. As used herein, the term "up to" a number or "no greater than" a number (e.g., up to 50) includes that number (e.g., 50), and the term "no less than" a number (e.g., 5 or greater) includes that number (e.g., 5).

[0066] The term "or" is generally used in its inclusive sense, e.g., meaning "and / or," unless the content clearly indicates otherwise. The term "and / or" refers to one or all of the listed elements or a combination of at least two of the listed elements.

Claims

1. 1. An adhesive article attachable to a substrate, comprising: an adhesive layer attachable to a major surface of the substrate; a releasable liner in contact with the adhesive layer; wherein the releasable liner comprises a release layer and a biodegradable polymer layer applied to the release layer, the release layer defining a structured surface in contact with the adhesive layer.

2. The article of claim 1 , wherein the biodegradable polymer layer comprises raised features that define a structured surface of the release layer.

3. The article of claim 1 , wherein the release layer comprises silicone.

4. 10. The article of claim 1, wherein the weight of the release layer is less than 15% of the total weight of the releasable liner.

5. The article of claim 1 , wherein the biodegradable polymer layer comprises polybutylene succinate.

6. The article of claim 5 , wherein the biodegradable polymer layer comprises a plant-based wax.

7. 10. The article of claim 1, wherein the releasable liner further comprises a paper layer applied to the biodegradable polymer layer and another biodegradable polymer layer, the other biodegradable polymer layer being applied to the paper layer on the opposite side from the biodegradable polymer layer.

8. The article of claim 1 further comprising a substrate attached to said adhesive layer, said substrate comprising at least one of PVC, PET, PLA.

9. The article of claim 8 , further comprising an ink layer on another major surface of the substrate opposite the adhesive layer.

10. 10. The article of claim 1, wherein the average peel force between the adhesive layer and the releasable liner is less than 135 grams force.

11. 1. A method of forming an adhesive article, comprising: providing an adhesive layer; laminating a releasable liner to the adhesive layer; wherein the releasable liner comprises a release layer and a biodegradable polymer layer applied to the release layer, the release layer defining a structured surface in contact with the adhesive layer.

12. coating the release layer onto the biodegradable polymer layer; embossing the release layer and the biodegradable polymer layer to provide the releasable liner; The method of claim 11 further comprising:

13. 1. A method of using an adhesive article, comprising: providing an adhesive article, the adhesive article comprising a releasable liner in contact with an adhesive layer, the releasable liner comprising a release layer and a biodegradable polymer layer applied to the release layer, the release layer defining a structured surface in contact with the adhesive layer; removing the releasable liner from the adhesive layer; laminating the adhesive layer onto a surface of an object; A method comprising:

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